JP-A-2002-337319 discloses an inkjet recording apparatus in which a so-called smear on a sheet is prevented. The inkjet recording apparatus includes an inkjet head, a discharging unit that discharges a sheet to a discharge position, a period determining unit that determines a period until the sheet comes into contact with the preceding sheet, and a speed controlling unit that controls speed of recording on the sheet.
In the inkjet recording apparatus, the period determining unit measures a recording ratio on the sheet and determines time when the conveyance of the sheet is stopped. The speed controlling unit stops a recording operation for a following sheet until the drying of the sheet is completed and resumes the recording operation after the drying is completed. This prevents a “smear” caused when the following sheet comes into contact with and rubs against the preceding sheet while ink does not completely dry.
However, time necessary for the drying of the sheet is determined assuming a worst condition among assumed environments of use, i.e., assuming a high humidity environment. Therefore, in an actual environment of use, drying time longer than necessary is secured. When the recording operation is stopped throughout the drying time, long time is required until the completion of printing. Therefore, there is room for improvement.
JP-A-8-52869 discloses a recording apparatus that determines, according to the reflectance on the surface of recording paper, whether the drying of ink is performed. The recording apparatus includes a recording head, a conveying unit that conveys the recording paper, a surface-state discriminating unit that discriminates a surface state of the recording paper, and a controlling unit that controls the conveying unit on the basis of a result of the discrimination by the surface-state discriminating unit.
The recording apparatus prints a black mark near the trailing end of the recording paper. The conveying unit moves the recording paper to below the surface-state discriminating unit. The surface-state discriminating unit measures the reflectance of the recording paper. When reflected light is outputted, the recording apparatus determines that the ink is not dried and stops the recording operation. When the output of the reflected light ends and it is determined that the ink is dried, the recording apparatus conveys the recording paper again, discharges the recording paper, and finishes the recording.
In the recording apparatus, since the black mark is printed last at the trailing end of the recording paper, the black mark dries latest in the recording paper. Therefore, the recording operation may be stopped regardless of the fact that the recording paper is actually dried. In this regard, there is room for improvement. Further, it is necessary to always print the black mark at the trailing end of the recording paper and the finish of the recording paper is deteriorated. In this regard, there is also room for improvement.